Ammann Peter, Naegeli Barbara, Rickli Hans, Buchholz Susanne, Mury Raymond, Schuiki Ernst, Bertel Osmund
Division of Cardiology, Department of Internal Medicine, Triemli Hospital, Kantonsspital St. Gallen, Zürich, Switzerland.
Clin Cardiol. 2003 Nov;26(11):521-4. doi: 10.1002/clc.4960261109.
Single-photon emission computed tomography (SPECT) sestamibi (MIBI) is an excellent tool for detection of coronary artery disease (CAD), preoperative risk assessment, and follow-up management after coronary revascularization. While the sensitivity of MIBI SPECT for detecting CAD has been reported to exceed 90%, the specificity ranges between 53-100%.
The study was undertaken to assess characteristics of patients with abnormal stress technetium Tc99m sestamibi SPECT (MIBI) studies without significant coronary artery diameter stenoses (< 50%).
Between January 1999 and November 2000, 270 consecutive patients were referred for coronary angiography due to reversible MIBI uptake defects during exercise. In 41 patients (15%; 39% women, mean age 59 +/- 9 years), reversible MIBI uptake defects were assessed although coronary angiography showed no significant CAD. These patients were compared with age- and gender-matched patients with perfusion abnormalities (39% women, mean age 60 +/- 9 years), due to significant CAD (coronary artery stenosis > 50%).
There were no significant differences between the two groups regarding body mass index, left bundle-branch block (LBBB), or method of stress test (dipyridamole in patients with LBBB or physical inactivity [n = 11] and exercise in all the others [n = 30]). Left ventricular hypertrophy (44 vs. 23%, p = 0.05) and left anterior fascicular block (LAFB) (17 vs. 0%, p = 0.005) were more common in patients with perfusion abnormalities with no significant CAD, whereas ST-segment depression during exercise (17 vs. 37% p = 0.05) and angina during exercise (15 vs. 29%, p = 0.02) were significantly less common than in patients with abnormal MIBI perfusion studies and angiographically significant CAD. Sestamibi uptake defects during exercise were significantly smaller in patients without significant CAD than in matched controls with significant CAD (p < 0.0004).
Of 270 consecutive patients, 41 (15%) referred to coronary angiography due to reversible MIBI uptake defects showed coronary artery stenoses < 50%. Twenty-six (10%) of these presented angiographically normal coronary arteries. The significantly higher proportion of left ventricular hypertrophy and LAFB in patients with reversible MIBI uptake defects without significant CAD suggest microvascular disease, angiographically underestimated CAD, and conduction abnormalities as underlying mechanisms.
单光子发射计算机断层扫描（SPECT）心肌灌注显像（MIBI）是检测冠状动脉疾病（CAD）、术前风险评估及冠状动脉血运重建术后随访管理的优秀工具。虽然据报道MIBI SPECT检测CAD的敏感性超过90%，但其特异性在53%至100%之间。
本研究旨在评估静息态锝Tc99m心肌灌注显像（MIBI）检查异常但冠状动脉直径狭窄不明显（<50%）患者的特征。
1999年1月至2000年11月期间，270例因运动中MIBI摄取可逆性缺损而连续接受冠状动脉造影检查的患者。41例患者（15%；女性占39%，平均年龄59±9岁），尽管冠状动脉造影显示无明显CAD，但仍评估了其可逆性MIBI摄取缺损。将这些患者与年龄和性别匹配的因显著CAD（冠状动脉狭窄>50%）导致灌注异常的患者（女性占39%，平均年龄60±9岁）进行比较。
两组在体重指数、左束支传导阻滞（LBBB）或负荷试验方法（LBBB或体力活动受限患者使用双嘧达莫[n = 11]，其他所有患者使用运动负荷试验[n = 30]）方面无显著差异。无明显CAD的灌注异常患者左心室肥厚（44%对23%，p = 0.05）和左前分支传导阻滞（LAFB）（17%对0%，p = 0.005）更为常见，而运动时ST段压低（17%对37%，p = 0.05）和运动时心绞痛（15%对29%，p = 0.02）明显少于MIBI灌注检查异常且冠状动脉造影有显著CAD的患者。无明显CAD患者运动时MIBI摄取缺损明显小于匹配的有明显CAD的对照组（p < 0.0004）。
在270例连续患者中，41例（15%）因可逆性MIBI摄取缺损接受冠状动脉造影检查，显示冠状动脉狭窄<50%。其中26例（10%）冠状动脉造影显示正常。无明显CAD的可逆性MIBI摄取缺损患者中左心室肥厚和LAFB比例显著更高，提示微血管疾病、冠状动脉造影低估的CAD及传导异常为潜在机制。
